chapman



(No Model.)

P. H. CHAPMAN.

EXTENSION GHANDELIBR.

No. 271,420. Patented Jan.30, 1883.

Nrrnp STATES" PATENT- .rrrcs.

FRANK H. CHAPMAN, OF MERIDEN, CONNECTICUT, ASSIGNOR TO THE CHAS. PARKER COMPANY, OF SAME PLACE.

EXTENSlON-CHANDELI ER.

SPECIFICATION formingpart of Letters Patent No. 271,420, dated January 30, 1883,

Application filed December 7, 1852. (No model.)

To all whom it may concern.-

Be it known that I, FRANK H. CHAPMAN,

of Meriden, in the county of New Haven and State of Connecticut, have invented anew Improvement in ExtensionChandeliers; and I do hereby declare the following, when taken in connection with the accompanying draw ings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in-

Figure 1, a front view; Fig. 2, a side view; Fig. 3, a vertical central section; Fig. 4, a transverse section; Figs. 5 and 6, the two parts of the clamp detached.

This invention relates to animprovement in that class of lamp-chandeliers which are constructed so that the lamp-supporting part may be raised or lowered upon the central rod, the said central rod made stationary at the ceiling, commonly called extension-fixtures. In this class of fixtures some device is necessnry to clamp the movable part upon the stationary part. Various devices have been devised for this purpose.

The object of my invention is to produce'a simple and easily-adjusted mechanism whereby astrong engagement between the movable and fixed parts maybe produced and be easily operated for the adjustment of the fixture; and it consists in the construction of the clamp, ing device, as hereinafter described, and more particularlyrecited in the claims.

In representing the fixture I show only so much as will-illustrate the clamping device. The movable part of the fixture may be any of the known constructions.

A represents the central rod by which the fixture is secured to the ceiling. It may be solid or tubular; B, a head or socket, to which the movable part of the chandelier or fixture is attached and arranged so as to slide upon the rod A. in the upper end of the socket is a recess, C, transversely to the rod. In this recess the clamping mechanism is arranged. This mechanism consists of a jaw, a, arranged to stand against the rod, and preferably with a vertical groove, 12, upon its face to bear against the rod and afford considerable clam ping-surface. On the back of this jaw is one or more circular inclined planes or cams, d, (see Figs. 4 and 5,) and between the jaw and the side of the recess a dog is arranged. This dog consists of a head, 0, having a stud,f, on its back fitting into a corresponding seat in the socket, so as to turn upon that stud as a center. The opposite side or face of the head 6 is constructed with inclines corresponding to the inclines on the jaw a, as seen in Figs. 4 and 6. From thehead an arm, 71, extends outward, by which the dog may be turned upon its seat as a center. The rod nearly fits the hole through the socket. The dog and cam nearly fill the space between the rod and the side of the recessin the socket. The jaw a cannot turn because of its clasp upon the rod. By turning the dog upon its center therefore the inclines between it and thejaw cause a transverse movement ot'the jaw toward the rod, and serve to press the rod toward the opposite-side of the hole in the socket, and thus clamp the one with the other. l/Vhen the dog is turned in the opposite direction it releases the grasp of the jaw upon the rod. Then the parts are free the one to move-upon the other.

On the opposite side of the head to the arm his a second arm, i, from which a spring, It, extends to a pin, l, the tendency of the spring being to turn the dog into the grasping or clamping condition. Hence the normal condition of the parts is that of clamping or securing the parts together to prevent the movement of one upon the other.

From the arm h a rod,m, extends downward to a convenient position for the hand of the person who is to adjust the fixture, and he has simply to pull upon that rod to overcome the power of the spring k. The pull upon the rod n turns the lever and dog upon the center or pivot], and correspondingly turns the inclines ot' the dog away from the correspondinginclines on thejaw (t. Then the fixture may be raised or lowered, as required, and when the rod is released the spring it reacts and causes thereturn of the dog, and through the inclines the automatic clamping of the parts together.

While I prefer to make the cam-acting surfaces between the head of the dog and the jaw,

they may be on the hack of the head to work too upon that side of the recess; or, instead of such cam-surface, the head may be provided with a central stud projecting toward the rod, screwthreaded, and the jaw with a hole correspondingly threaded, so that thejaw being prevented from rotation, the partial rotation of the heador dog will impart a transverse movement to thejaw, according to the pitch of the thread. I therefore do not wish to limit my invention to the particular construction of the cam or working surfaces, it only being essential to my invention that there shall be a jaw to bear against the rod, a dog arranged between said jaw and the socket, and so that a partial rotation of the dog will impart a corresponding transverse movement to thejaw to clamp the rod and socket together or release them, according to the direction in which the dog is turned. I

Instead of employing the spring to automatically apply the clamping device, this may be done by the operator turning the dog in the opposite direction to that which he turned it in applying the clamp; or if the spring is used it may be otherwise applied, it only being essential that if it is applied it shall be so as to produce the automatic action of the clamping device.

I claim 1. In an extension lamp-fixture, the combination of the stationary or central part, A, by which the fixture is hung, the socket B, to which the movable part of the fixture is attached, said socket arranged to slide freely on the rod, the socket constructed with a transverse recess, ajaw, a, arranged in said recess againstthe rod, and a dog between said jaw and the side of the recess, the said dog hung for partial rotation, and having an arm extending outward by which rotation is imparted to the dog, the said dog constructed substantially as described, whereby its partial rotation imparts a transverse movement of the jaw toward the rod to clamp or release the rod, according to the direction in which the jaw is turned, substantially as described.

2. In an extension lamp-fixture, the combination of the stationary or central part, A, by which the fixture is hung, the socket B, to which the movable part of the fixture is attached, said socket arranged to slide freely on the rod, the socket constructed with a transverse recess, a jaw, a, arranged in said recess against the rod, and adog between saidjaw and the side of the recess, the said dog constructed with a stud,f, to take a bearing in acorresponding seat in the side of the recess and form a center upon which the dog will rotate, the meeting faces of the dog and jaw camsha-ped, whereby rotation of the dog will impart transverse movement to thejaw to clamp the socket and rod, substantially as described.

In an extension lamp-fixture, the combination of the stationary or central part, A, by which the fixture is hung, the socket B, to which the movable part of the fixture is attached, said socket arranged to slide freelyon the rod, the socket constructed with a transverse recess, ajaw, (0, arranged in said recess against the rod, a dog between said jaw and the side of the recess, the said dog hung for partial rotation, and with an arm extending outward by which rotation is imparted to the dog, the said (log constructed substantially as described, whereby its partial rotation imparts a transverse movement of thejaw toward the rod to clamp or release the rod, according to the direction in which the jaw is turned, and a spring to draw the parts into the clamping position, substantially as described.

F tANK H. CHAPMAN.

' Witnesses:

DEXTER WV. PARKER, RALPH A. PALMER. 

